There was no written form of Japanese until the Chinese system was adopted.
This has over 10,000 characters of which over 2000 can be used for personal names so many combinations are possible but in reality, only about 6500 are commonly used. It originated in China in the Kwan dynasty (BC 202-AD 220) and is derived from older Chinese characters.
This is the old Japanese alphabet of 46 letters which each represent a sound. It dates back to the Heian era (785-1185). Originally, it was never used in conjunction with Kanji or Katakana but this can be done in modern Japanese. Only women use these letters for their names.
These letters are partially derived from Kanji and were used with it to help show how it was pronounced in Japanese in the Meiji era. Nowadays, foreign words are often written in katakana.
This is the system of Romanization or conversion into western script. The spelling of a word in English usually reflects its pronunciation in Japanese.